Field of the Invention
The present invention relates to calculation of the consumption amount of a color material in a printing apparatus.
Description of the Related Art
In an electrophotographic printing apparatus, a potential latent image optically drawn on a photosensitive member is developed with toner, and the toner image is transferred to a conveyed paper sheet and fixed on the sheet with heat and pressure, thereby creating a printout product. When the toner runs out during creation of the printout product, the productivity of the job is reduced. To avoid this, in many printing apparatuses, a mechanism for detecting the residual amount of the toner and informing a user of this is prepared.
For example, there is available a method of accumulating the number of printing pixels of an image, multiplying the accumulation value with a toner weight per pixel, and predicting a toner amount to be consumed. Since the toner amount to be consumed varies depending on a temperature, humidity, and state of the apparatus, the toner weight per pixel is corrected by outputting and measuring a patch in Japanese Patent Laid-Open No. 2010-102317.
However, the toner consumption amount for a print page having a single large tone region is different from that for a print page having small discrete tone regions. For example, to print small tone regions discretely, it is hard to attach toner to a small region to result in a small toner consumption amount. For this reason, in the related art described above, the toner consumption amount depending on the difference in the areas of the tone regions cannot be accurately predicted.